Transient 3D Shape Measurement Method Based on Pulsed-Laser-Illuminated Stroboscopic Structured Light

Rotor blades in aero-engines operating in sand-laden environments are highly susceptible to particle-induced erosion. Conventional sand ingestion experiments primarily rely on post-test disassembly, which lacks the capability for real-time surface shape analysis. To overcome this limitation, this study proposes a high-precision three-dimensional (3D) shape measurement method for ultrafast dynamic scenarios, based on pulsed laser illumination and stroboscopic structured light. In the proposed approach, a pulsed laser is employed to illuminate a physical grating, generating stroboscopic structured fringe patterns that are projected onto high-speed rotating blades. The deformed fringe images are synchronously captured by a high-speed camera and processed using Fourier transform profilometry (FTP) to reconstruct fine surface features with high accuracy. Compared with conventional LED-based stroboscopic systems, the pulsed-laser-based scheme effectively suppresses motion blur and significantly improves image intensity under ultra-short exposure conditions. Experimental results demonstrate that stable and high-quality fringe acquisition can be achieved at high rotational speeds. The method enables precise quantification of micro-scale defects, such as scratches and pits, providing a reliable solution for in situ monitoring and performance evaluation in aero-engine sand ingestion tests.